The invention will be described with particular reference to its application to the mounting of an excavator bucket to the operating arm of an excavator. It will be appreciated by those skilled in the art, however, that the invention has applicability to the mounting of other forms of implements or attachment to the operating arm of excavators or other earthmoving equipment.
The most common form of mounting to connect an excavator bucket to the operating arm of the excavation machine utilises a pair of spaced mounting pins extending between a pair of substantially parallel ears which constitute part of the bucket. The mounting pins are engaged by an attachment on the end of the operating arm of the excavator whereby the bucket is locked to the arm and is able to pivot about the axis of one of the mounting pins, under the influence of an hydraulically or electrically actuated lever to change the bucket aspect.
A difficulty with mounting excavator buckets to the arms of excavators is that the dimensions of the ear width (spacing), pin diameter and pin spacing varies between manufacturers. In some cases, these dimensions also vary within a manufacturer, for machines of different capacities. Thus, a Caterpillar 312C excavator has an ear width of 221 mm, a pin spacing (centre to centre) of 407 mm and pin diameters of 65 mm. However, the equivalent class Komatsu excavator has an ear width of 261 mm, a pin spacing of 375 mm and pin diameters of 60 mm. A Sumitomo SH120 machine has an ear width of 235 mm, a pin centre spacing of 385 mm and pin diameters of 65 mm.
Accordingly, with present mounting systems, it is not possible to mount a bucket manufactured for one machine to the excavator arm of a different manufacturer.
This, therefore, requires machine owners and users to have a large range of substantially identical buckets for machines of different manufacturers. This is both highly inefficient, time consuming and wasteful of resources.
The specification published under International Publication No. WO 01/83894 A1 discloses one proposed arrangement to attempt to obviate difficulties of present mounting systems. The specification discloses the use of bushes that engage through enlarges holes in the ears, or side plates, of the implement mounting. Each bush has an eccentrically positioned hole to receive a mounting pin. The position of the pin relative to the side plates is adjustable by relative rotation of each bush. A plurality of locating screws located the bushes in desired positions. With this arrangement, the relative position of the respective pins is limited to the spacing of the locating screws. Further, in the dirty, dusty, rough environment in which the implements are used, screws and locating pins are difficult to use. Also, the provision of many locating screws reduces the structural strength of the side plates.
Similar problems exist with the structure disclosed in International Publication No WO 03/069077 A1, whereas the disclosure in specification WO 99/06317 provides only limited adjustment of the relative positioning of the pins.
It is therefore desirable to provide a bucket mounting system which obviates, to a large extent, the disadvantages to which reference is made above.
It is also desirable to provide a bucket mounting system which enables buckets of one manufacturer to be mounted to the machine arm of a different manufacturer.
It is also desirable to provide a bucket mounting system which is simple and easy to use, which can accommodate a variety of different mounting arm dimensions, and which is simple and quick to use.
It is also desirable to provide a mounting system for excavator buckets and other equipment which is economic to manufacture and use.